Acidification and Liming of River Vikedal, Western Norway. A 20 Year Study of Responses in the Benthic Invertebrate Fauna

This paper deals with benthic invertebrate population responses to acidification and liming in the lower part of River Vikedal. In 1979 the river showed signs of increasing acidification. Highly sensitive invertebrates like the mayfly Baetis rhodani were present in the river in low abundance, but disappeared in the subsequent years. In order to re-establish a non-toxic water quality for fish, liming of the spring snowmelt to a minimum of pH 5.7 was started in 1987. During the later years liming has been successively increased. The invertebrate fauna showed a slow, but positive, response during the first years after liming, especially during autumn. B. rhodani recolonized the river in low density, but the spring cohort was still weak. Since 1994 the lime dosage was increased to secure a minimum pH of 6.3 during spring snowmelt. This has resulted in an overall increased biodiversity in the limed section of the river. Several acid-sensitive species, like both cohorts of B. rhodani and freshwater snails have colonized this part of the river. Simultaneously biodiversity in the unlimed reference sites has slightly improved during the last years. This is correlated with decreased sulphur deposition and improved surface water chemical conditions.     

Impacts of acid precipitation on coniferous forest ecosystems

This paper summarizes the results from current studies in Norway. One main approach is the application of artificial acid ‘rain’ and of lime to field plots and lysimeters. Application during two growth seasons of 50 mm mo^?1 of ‘rain water’ of pH 3 to a podzol soil increased the acidity of the humus and decreased the base saturation. The reduction in base saturation was mainly due to leaching of Ca and Mg. Laboratory experiments revealed that decomposition of pine needles was not affected by any acid ‘rain’ treatment of the field plots. Liming slightly retarded the decomposition. No nitrification occurred in unlimed soils (pH 4.4-4.1). Liming increased nitrification. The soil enchytraeid (Ohgochaeta) fauna was not much affected by the acidification. Germination of spruce seeds in acidified mineral soil was negatively affected when soil pH was 4.0 or lower. Seedling establishment was even more sensitive to increasing soil acidity. Analysis of throughfall and stemflow water in southernmost Norway reveals that the total deposition of H₂SO₄ beneath spruce and pine is approximately two times the deposition in open terrain. A large part of this increase is probably due to dry deposition. Increased acidity of the rain seems to increase the leaching of cations from the tree crowns. Tree-ring analysis of spruce (Picea abies (L.) Karst.) and pine (Pinus sylvestris L.) has been based on comparisons between regions differently stressed by acid precipitation and also between sites presumed to differ in sensitivity to acidification. No effect that can be related to acid precipitation has yet been detected on diameter growth.     

A radiological study on the development of vertebral deformities in cultured Atlantic salmon (Salmo salar L.)

This study investigated the development of skeletal deformities in individually tagged Atlantic salmon (n = 805) from the parr stage (Sept 2001, 70 g mean ± 34 g S.D.) until 10 month after transfer to seawater (Feb 2003, 3040 g mean ± 1097 g S.D.). A subgroup of the total population (n = 129) was radiographed as parr (Feb 2002) and again 10 months after transfer to seawater (Feb 2003). Eight percent of the males matured sexually during their first autumn in sea (jack), and were excluded from further analysis. Based on an external examination of each fish (n = 773), 1.8% (n = 14) developed skeletal deformities (0.1% operculum deformities (n = 1), 0.4% jaw deformities (n = 3), 1.3% vertebral deformities (n = 10)) during the experiment. Based on evaluation of radiographs (n = 129), the prevalence of vertebral deformities was 7.0% (n = 9) at the parr stage, and 12.4% (n = 16) 10 months after transfer to seawater. From radiographs, longitudinally compressed vertebral bodies without intervertebral spaces were classified as ankylosis and compression, longitudinally compressed vertebral bodies with intervertebral spaces were classified as compressions, and dislocated vertebral bodies with a normal morphology and without intervertebral spaces were classified as ankylosis and dislocation. Of the fish that developed deformities during the experiment, 8 had ankylosis and compressions, 7 had compressions and 1 had ankylosis and dislocation. Ankylosis and compression developed in the region between vertebrae number 1 and 16, whereas compressions developed in the region between vertebrae number 13 and 49. Most of the individuals with compression 10 months after transfer to seawater had normal vertebral columns as parr, whereas all individuals with compression and ankylosis 10 months after transfer to seawater had deformed vertebral columns as parr.     

Some chemical and biological properties of a protein concentrate from nigerseed (Guizotia abyssinica Cass.)

A protein concentrate has been prepared from nigerseed (Guizotia abyssinica Cass.) by a method involving extraction of the protein with NaCl-solution.The protein concentrate contains about 65% of protein (N×5.5) calculated from the dry weight, and the amino acid pattern is fairly well balanced. The chemical score is 82 calculated from the A/E values.The nutritional value of the product has been tested on young rats. These tests revealed the presence of antinutritional factors in the protein concentrate. The PER was only 1.5.It was also found that the rate of digestion by pancreatin was much slower for the protein concentrate than for casein, possibly due to enzyme resistent linkages.The protein concentrate seems to be devoid of hemagglutinin activity. Antibodies against the nug extracts could not be found.

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Zusammenfassung Ein Proteinkonzentrat wurde aus Nug-Samen (Guizotia abyssinica Cass.) durch eine Methode gewonnen, die eine Extraktion des Proteins mit NaCl-Lösung einschließt.Das Proteinkonzentrat enthalt etwa 65% Protein (N x 5,5), berechnet auf das Trockengewicht. Das Aminosäuregleichgewicht ist relativ gut balanziert. Die chemical score nach den A/E Werten berechnet, beträgt 82.Der Nährwert des Produktes ist an jungen Ratten getestet worden. Diese Tests zeigten das Vorhandensein von Antinähr-Faktoren im Proteinkonzentrat. Die PER (protein efficiency ratio) betrug nur 1,5.Es wurde außerdem festgestellt, daß die Geschwindigkeit der enzymatischen Verdauung (mit Pankreatin) für das Proteinkonzentrat viel langsamer abläuft als für Casein. Dieses ist vielleicht bedingt durch Enzymresistente Bindungen.Das Proteinkonzentrat scheint von Hämagglutininaktivität frei zu sein. Es wurden keine Antikörper gegen Nug-Extrakte gefunden.

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Résumé Une solution concentrée de protéine a été préparée de grains de nug (Guizotia abyssinica Cass.) par une méthode contenant l'extraction de la protéine avec la solution NaCl.La solution concentrée contient environ 65% de protéine (N X 5,5) calculée du poids sec, et le modèle des aminoacides est assez bien balancé. Le chemical score est 82 calculé des valeurs A/E. La valeur nutritive du produit a été éprouvé à de jeunes rats. Ces épreuves ont révélé la présence d'éléments antinutritives dans la solution concentrée de protéine. La PER (protein efficiency ratio) était seulement 1,5.On a aussi trouvé que la rapidité de digestion enzymatique (avec la pancréatine) pour la solution concentrée de protéine était beaucoup plus lente que pour le casein. Ceci est peut-être du à des liaisons qui résistent aux enzymes.Il semble que la solution concentrée de protéine manque d'activité hemagglutinine. On n'a pas pu trouver des anticorps dirigés contre les extraits de nug.

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CNU Report No. 34.     

Seasonal reproduction of male Gambusia holbrooki (eastern mosquitofish) from two Florida lakes

Sixteen monthly collections of adult male Gambusia holbrooki (eastern mosquitofish) were obtained from two lakes in central Florida, USA. Lake Woodruff and Lake Apopka are 36 miles apart, but differ in several environmental parameters. Compared with Lake Woodruff, Lake Apopka is warmer, more shallow in sampling areas (particularly during drought conditions; approximately 15–90 cm in Lake Apopka versus 60–120 cm in Lake Woodruff), more turbid, and more heavily contaminated with nutrients and industrial and agricultural chemicals. Here, we present detailed information on seasonal reproduction patterns in mosquitofish in their native range and compare patterns between fish from the two lakes. Male mosquitofish were reproductively active from spring through fall. Spermatogenesis, which is regulated in part by 11-ketotestosterone, ceased in October, and fish stored spermatozoa through the winter for immediate fertilization of offspring in the spring. Compared with Lake Woodruff, fish from Lake Apopka tended to be larger and have longer gonopodia and greater gonado- and hepato-somatic indices (GSI and HSI). High GSI in Apopka fish correlated with greater spermatid production, but fewer mature spermatozoa and either the same or lower sperm counts and sperm viability. Taken together, these observations suggest that differentiation of spermatids to spermatozoa is disrupted in Apopka fish, leading to reductions in fertility in some months. Delivery of sperm to females could also be affected in Apopka fish, which exhibit lower prevalence of efferent duct tissue in the testes during the summer.     

Quantitative PCR shows propagation of <Emphasis Type="Italic">Plasmodiophora brassicae</Emphasis> in Swedish long term field trials

Clubroot (Plasmodiophora brassicae) is a serious soil-borne disease in brassica crops world-wide. We report on a time series of soil samples from Swedish long-term fertility trials started in 1957, 1963 and 1966, which were analyzed for the amount of P. brassicae DNA. The crop rotations included a brassica crop every 4 or 6 years. All experimental sites with a 4-year rotation of oilseed rape, except one with calcium carbonate in the soil profile, showed high (>1000 fg DNA g^?1 soil) levels of P. brassicae DNA after 9, 11 and 12 rotations. In contrast, detectable levels (>5 fg DNA g^?1 soil) of P. brassicae were found only at one of five sites with a 6-year rotation of spring oilseed rape. In years with high levels of P. brassicae DNA, low yield was reported and a subsequent decline in P. brassicae DNA in soil was observed. Different NPK (nitrogen/phosphorus/potassium) fertiliser regimes resulted in similar P. brassicae DNA levels. The robustness and reliability of the method applied was verified by analyses of soil from individual plots compared with a mixture of plots and by repeated analyses of selected samples, which showed that P. brassicae DNA remained stable during dry storage.     

Drainage in Sweden -the past and new developments

Land drainage in Sweden has been regulated in various laws since the Middle Ages. The lowering of lake surfaces and the ditching of wetlands has been considered a valuable task to gain cultivable land, and more recently, to promote forest growth. However, in recent years the debate surrounding drainage in forests has been a matter of considerable discussion. The dry and hot summer of 2018 has awakened new views on the subject. Monitoring has shown an exceptionally low groundwater levels countrywide. Especially the islands of Öland and Gotland have faced groundwater shortages and the groundwater levels are still low in both small and large aquifers. Drainage within forest land has lacked any scientific basis until rather recently. Still, it has been a supported activity during the twentieth century. However, this has gradually as knowledge on the activity has increased and the ecology of downstream water bodies has been considered. Today, only the rinsing of existing drainage is actively practised, and it is surrounded by a number of recommendations which are still under discussion.     

Excretion of Methoxychlor in Cow Milk Following Dermal Application

The concentrations of methoxychlor in cow milk and plasma were determined following a cutaneous application of a non-commercial emulsion and an intravenous injection of a solution containing 5 and 1 g methoxychlor, respectively. Furthermore, some pharmacokinetic parameters were estimated and the results were evaluated toxicologically by comparison with the acceptable daily intake.Maximum concentration of methoxychlor in milk, found 2 days after dermal administration, was 0.062 ppm, decreasing to around 0.005 ppm 30 days later.From the results, a distribution volume greater than 200 times the body volume, a dermal absorption of around 1/5 of the topically applicated dose, and a half-life of 8–10 days were estimated.It was concluded that the levels in cow milk, following dermal application with an emulsion of methoxychlor did not represent any threat to human health and methoxychlor was recommended as a pesticide of choice for use on dairy cows.